The characteristic changes are going on, I think there is only one area left (but an annoying area.
) And then there will be the AI tweaks JLS mentioned.
I tend not to sign on any treaty above Trade Alliance with close Empires, and I will never, ever, sign a Partnership treaty. (At least against the AI) Research helps your future enemy, while resources are much less of a problem. In fact, having a Trade agreement with your future opponent can be useful, since he/she will spend more resources and have a higher income. The removal of the trade agreement might collapse his/her economy. *Evil snicker* That is, when you are playing with a human obviously.
But then, I am somewhat a isolationist in SEIV, always setting up frontiers that should not be crossed. (Who said minefields?) Hence the problem with trade agreements. I wish you could have a trade agreement without setting up a military trust between the two Empires.
My dream is unfortunately impossible to set up in multiplayer, except if you do... erh... assimilate all the other Empires.